1. Field of the Disclosure
This disclosure relates generally to methods and apparatus for use in wellbores.
2. Description of the Related Art
Wellbores or boreholes are drilled in the earth's subsurface formations for the production of hydrocarbons (oil and gas), utilizing a rig (land or offshore) and a drill string. The drill string includes a tubing (jointed pipes or a coiled tubing) and a drilling assembly (also referred to as a “bottom hole assembly” or “BHA”). To drill the wellbore, a drill bit attached to the bottom of the BHA is rotated by rotating the drill string at the surface and/or by a drilling motor (also referred to as “mud motor”) disposed in the BHA. The BHA typically carries a variety of devices useful in drilling the wellbores. Such devices may include sensors for measuring inclination and azimuth of the BHA assembly, force application devices that apply force on the wellbore to change the drilling direction, etc. The BHA also carries a variety of downhole tools, referred to as the logging-while-drilling (“LWD”) or measurement-while-drilling (“MWD”) tools, for estimating parameters of the formation surrounding the wellbore. The BHA often exceeds 30 meters in length and the various tools in the BHA carry sensitive sensors and electronic components that can be damaged due to great stress on the BHA during drilling of the wellbore. Weight-on-bit (WOB), BHA rotational speed (RPM) and drilling direction are controlled to drill the wellbore at desired rates of penetration along a desired path and to maintain the BHA operating parameters, such as bending, stress, and deflection, etc. within acceptable limits. Preexisting simulation software or models, referred to as the “engineering software or models” are often used to simulate the BHA operating parameters and the simulation results are then used to choose the optimal range of drilling parameters, such as WOB and RPM. Computing BHA operating parameters using preexisting simulation models generally take a relatively long time. Such models are generally not suitable for computing the BHA operating parameters during drilling of the wellbore because the downhole drilling conditions often changes continually. Thus, there is a need for a model that can provide simulation results relating to one or more BHA operating parameters during the drilling operations.